Posted by **jenny** on Wednesday, February 27, 2013 at 6:51pm.

A box of mass 3 units rests on a horizontal rough surface and is tied to

the end of a rope. Peter pulls on the rope and exerts a force of magnitude sqrt(2g)

with the rope making an angle of Pi/4 with the horizontal. Given that the box

is on the point of slipping, show that the coeffcient of friction is 1/2.